Synthesis of α-Aminophosphonates in the Presence of a Magnetic Recyclable Fe3O4@SiO2-2mimSO3H Nanocatalyst

A highly efficient magnetic Bronsted acid catalyst was synthesized based on immobilization of 2-methylimidazole functionalized by chlorosulfonic acid on the surface of silica-coated magnetic nanoparticles (Fe3O4@SiO2-2mimSO(3)H). The catalyst has an excellent activity and recyclable for at least 6 reaction runs and is proven to be highly effective in the synthesis of alpha-aminophosphonate compounds in a green way. The facile recovery of the catalyst is carried out by applying an external magnet device. It is both green and efficient. The catalyst was fully characterized by techniques of TEM, SEM, FT-IR, TGA, and elemental analysis (CHNS).